<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>2.1 什么是栅格系统-1</title>
    <style>
        * {
            box-sizing: border-box;
            padding: 0;
            margin: 0;
        }

        html, body {
            height: 100%;
        }

       .grid {
            background-image: url(img/grid.png);
            -webkit-background-size: 100% 100%;
            background-size: 100% 100%;
       }
       .container {
            height: 100%;
       }
       .none {
            display: none;
       }
    </style>
    <link rel="stylesheet" href="css/grid.css">
</head>
<body class="grid">
    <div class="container grid none"></div>
</body>
</html>